I recently went for Hampta Pass trek. The trek was well organized and we did acclimatize for a day and started the trek next day.

Initial two days of trek went quite well. On 3rd day of trekking, I started feeling breathlessness, fatigue and shivering by the time we reached next camp. At night, I was found breathing heavily, and my oxygen level was found to be around 32%. This was a serious condition as per the people responsible for trekkers, though I was not feeling that alarmed other than dizziness and getting out of breath too soon.
But obviously, I wasn't allowed to go further and next day I descended back to previous camp along with a trekking assistant, who is now a good friend of mine. Anyway, when I returned to base camp, I still felt fatigue and some fever.
Now when I try to think of the reason for it, it may had been possible due to lack of drinking water on 2nd day plus smoking a cigarette on same day. Also as I felt some headache on 2nd night, I consumed Combiflam which might have been a heavy medication on altitude. But, anyway I recovered in few days.

Now, after 8 months, I am planning to trek Sar Pass. Though I am fully confident that I can make it, but still I have some doubt if I may face same problem again.

My concern is to know, can low oxygen level to such extent affect some of my brain capabilities permanently, or any other similar issue? Can anyone, knowledgeable in this regard, guide me or give their views.
Thanks in advance.

First of all I have to say I can't quite place your statement "my oxygen level was found to be around 32%". If it's the oxygen saturation that you are referring to, well, at 32% you're dead! Normal oxygen saturation at sea level is above 95%, usually close to 100%. If it's 90%, get yourself to a hospital. At higher elevations, normal values are lower. At 11 000 ft, a normal value is just above 90%; at 16 000 ft around 80%. When well acclimatized, values should be higher, though not close to 100%. Well acclimatized, I once measured 91% at just over 14 000 ft. My heart rate was well above normal, but apart from that I felt fine.

Without exactly knowing what the 32% stands for, I'll accept that your oxygen levels were too low, possibly even so low that it was unsafe to continue even if you wouldn't have had any other symptoms. Normally, 11 000 ft is fairly low to get serious altitude sickness. Feeling a bit lightheaded, having a mild headache, fatigue, that's all to be expected. Not everybody reacts the same, but if you go straight from sea level to 11 000 ft, this is normal. If it's worse, then the remedy is to descend.

Assuming that you're wearing enough clothes to keep warm and are not sweaty from exertion, shivering is a bad sign. I would not interpret it as an indicator of altitude sickness, but you're sick nonetheless. Fever is another indication that you're not well, more so because you had that lower down, back in base camp. In hindsight, I think you were sick by the 3rd day, and on top of that you may well have had altitude sickness (AMS, not yet HAPE or HACE).

While AMS won't kill you, if you ignore it, it may develop into HAPE or HACE, which can be deadly, although that's unlikely as low as 11 000 ft. Still, the golden rule is that if you're sick at altitude and you're not sure whether it is AMS, play it safe and descend. Fortunately, AMS is quickly and totally reversible. Just descend until you feel fine. You can even try ascending again the next day. As your body is acclimatized more, it will probably go better. Mind you, some people acclimatize better than others.

As for your next trek, you can take a few measures to help with acclimatization. The easiest one is to drink more: being well hydrated helps with acclimatization. The second measure is to spend some some days at altitude before the trek, so you are already somewhat acclimatized. Finally, it's not the one cigarette, but being a smoker in the first place that may already have affected your lung capacity. Also, smoking results in elevated carbon monoxide in your blood, which binds much stronger to haemoglobin than oxygen, thereby decreasing the capacity of your blood to get oxygen to your muscles. However, I don't believe the effects of only one cigarette will last very long. The third and most difficult measure is to stop smoking.

Click here for much more information about altitude sickness.

And, last but not least: enjoy the mountains!

There is at least one research paper (Ie. Not a body of evidence by any means)which shows the Brain gets minor damage at altitude, but I wouldn't pay too much attention to that given the number of people who go to high altitudes and don't suffer recognisable effects. That was found to be general across the population so it wouldn't effect you anymore than others if the research findings were accurate. It was also at altitudes well above 11,000 feet I think.

There is also a research paper that suggests a small part of the population, with a certain heart characteristic, don't do altitude very well relative to the rest of the population. You can find that out by safely trying altitude again and again. That Doesn't mean your heart is susceptible to heart disease I don't think.

In your case, It may have been a combination of lack of water and a fever coming on that led to your weakened body struggling with the effort (not sure how quickly you climbed) and reduced oxygen saturation, bringing on symptoms of altitude sickness. Drink plenty of water, and gain elevation gently. Ascend in a nice,moderate pace with adequate rests and ensure you will be safe in case you get sick again. Do a google on altitude sickness and look for reports from agencies that specialise in altitude or other auhtorititavive sources.

Mate, you probably just need to harden up a bit. The Mountains are a tough place and only the tough can survive up there. The more that you can suffer means the more that you can climb. In the books it says that altitude sickness doesn't begin until 5000 meters, though I have seen cases as low as 4000 meters in North America. I just put it down to lack of fitness. If you are having a tough time in the mountains then go and run a Marathon or something that gets you really fit and then come back and you will most probably find that you won't have those strange problems at low altitude any more.

Yank-Tank wrote:Mate, you probably just need to harden up a bit. The Mountains are a tough place and only the tough can survive up there. The more that you can suffer means the more that you can climb. In the books it says that altitude sickness doesn't begin until 5000 meters, though I have seen cases as low as 4000 meters in North America. I just put it down to lack of fitness. If you are having a tough time in the mountains then go and run a Marathon or something that gets you really fit and then come back and you will most probably find that you won't have those strange problems at low altitude any more.

I don't know which books you have read, but this is nonsense. First of all, being fit doesn't prevent mountain sickness. Secondly, AMS can happen from about 2500 m, though it won't kill you. HAPE and HACE can, and according to the UIAA medical commsion, it can start from as low as 3000 and 4000-5000 m respectively. Misinformation is dangerous. Believing that altitude sickness doesn't begin until 5000 m and to ignoring the symptoms can cost you your life.

- UIAA statement on AMS, HAPE and HACE
- SP has an excellent article on Expedition Medicine; read the chapter about Altitude Illness

I read books on high altitude study's that they have done in the Himalayas. But they are all fit over there. Take some unfit Americans though and they get sick at extremely low altitudes. So you say this can't be fixed, then the dude had better not ever risk even attempting to go to Nepal then or the local ski field.

If you think that fitness doesn't play a part in it all thenI think it is you who is dreaming. buddy.

I think that maybe above 5000 meters it might be more about genetics in cases of altitude sickness but below that if you are getting sick then you can change and train to obtain these altitudes for sure.

I don't think toughening up is that important when it comes to altitude sickness. I think fitness helps cos your body isn't as stressed while trying to adjust to less O. But I've seen fit young people suffer from altitude while older (nanas), larger people have had no problems from 3,400 to 5,500 metres.

I guess those guys won't ever be able to climb much then. We have a heap of peaks over 3000 meters here in New Zealand and I have never herd of a single incident of altitude sickness.

I use to get headaches above like 13000 feet, then I got real fit and never had the problem again.